Kwon, Hi Jeong

AbstractBackgroundBK virus (BKV)‐associated hemorrhagic cystitis (BKV‐HC) is a severe complication after hematopoietic stem cell transplantation (HSCT). Cidofovir (CDV) has emerged as an effective agent for the treatment of BKV nephropathy, but its use for BKV‐HC in pediatric HSCT recipients has not yet been established as a standard therapy.Patient and methodsWe retrospectively investigated the efficacy and safety of CDV therapy for patients with BKV‐HC at a single institution and analyzed the clinical management outcomes.ResultsFrom April 2009 to July 2011, 12 patients developed BKV‐HC at a median of 37 days after transplant (range 15–59 days). The cumulative incidence was 9% and the median peak of the urine BKV load was 2.5 × 1010 copies/mL (range 1.4 × 109–1.2 × 1011 copies/mL). Eleven patients received intravenous CDV (5 mg/kg/dose, with probenecid), whereas 1 patient received CDV (5 mg/kg/dose, without probenecid) intravesically. The median duration of therapy was 25 days (range 9–73 days), and a median of 2 doses was given (range 1–4). A reduction of ≥1 log in the BKV load was found in 11 patients, while 1 patient did not have any significant change in BKV load. Clinical improvement was observed in all cases, and no HC‐related death was observed. CDV‐related toxicity occurred in 1 patient (8%) and spontaneously resolved.ConclusionsCDV appears to be an effective and safe treatment for BKV‐HC in pediatric HSCT recipients, but prospective trials are warranted to support its use.